BIO 112 - History of Life on Earth Flashcards

Vocabulary flashcards generated from BIO 112 lecture notes covering topics such as early life origins, radiometric dating, endosymbiosis, geologic time, plate tectonics, mass extinctions, and evolutionary concepts.

Monotremes

One of the three major living mammal groups, comprising $5$ species.

Marsupials

One of the three major living mammal groups, comprising $324$ species.

Eutherians

Placental mammals representing one of the three major living mammal groups, comprising $5{,}010$ species.

Alkaline Vents

Deep-sea hydrothermal vents characterized by a pH of $9-11$ and temperatures between $40-90^\circ\text{C}$, which provided suitable conditions for stable organic compounds.

Murchison Meteorite

A meteorite containing more than $80$ amino acids along with lipids, simple sugars, and nitrogenous bases.

Montmorillonite

A soft clay mineral common on early Earth that greatly increases the rate of vesicle formation.

Protocells

Fluid-filled vesicles with membrane-like structures that exhibit key properties of life including simple growth, reproduction, and metabolism.

Ribozymes

RNA molecules that function as enzymes and can catalyze chemical reactions, including making complementary copies of short stretches of RNA.

Strata

Sedimentary rock layers that serve as the richest source of fossils.

Radiometric Dating

A method used to date rocks and fossils based on the decay of a radioactive parent isotope into a stable daughter isotope.

Half-Life

The amount of time required for $\frac{1}{2}$ ($50\%$) of a radioactive parent isotope to decay.

Radiocarbon Dating

A dating method comparing carbon-14 with carbon-12, capable of dating fossils up to about $75{,}000$\,years old.

Stromatolites

The oldest known fossils, dating to about $3.5$\,billion years ago, formed by sedimentary layers accumulating on bacterial mats.

Serial Endosymbiosis

A sequence of endosymbiotic events where an ancestral prokaryote engulfed an aerobic bacterium (mitochondrion) to form a heterotrophic eukaryote, followed by engulfing a photosynthetic bacterium (plastid).

Ediacaran Biota

An early group of soft-bodied multicellular organisms that lived from $635$ to $541$\,million years ago.

Cambrian Explosion

A period approximately $535$ to $525$\,million years ago marked by the sudden appearance of fossils resembling modern animal phyla and the first strong evidence of predator-prey interactions.

Theory of Plate Tectonics

The theory stating that Earth's crust is composed of major plates floating on the underlying mantle.

Pangea

A supercontinent that formed approximately $252$\,million years ago.

Permian Mass Extinction

A mass extinction event $252$\,million years ago that wiped out approximately $96\%$ of marine animal species.

Cretaceous Mass Extinction

A mass extinction event $66$\,million years ago in which all dinosaurs except birds went extinct, caused by a meteorite impact at the Chicxulub crater.

Chicxulub Crater

A meteorite impact site near the Yucatán Peninsula associated with the Cretaceous mass extinction.

Adaptive Radiation

The rapid evolution of diversely adapted species from a common ancestor following mass extinctions, evolution of novel characteristics, or colonization of new regions.

Evolutionary Tinkering

The concept that evolution operates by modifying existing forms over time rather than creating structures in anticipation of future utility.